Wireless power transmission device

ABSTRACT

A coil structure for wireless power transmission is provided. The coil structure comprises: a primary resonance coil wound in a spiral shape around a centripetal point; a primary induction coil, which supplies power to the primary resonance coil in a nonconnected state with an input or output terminal of the primary resonance coil and is wound in a spiral shape on a substantially same plane around a substantially same centripetal point as the centripetal point; a switch configured to be parallel with the primary resonance coil so as to control the ON and OFF of an operation of the primary resonance coil; and a capacitor coupled to the primary resonance coil so as to form a magnetic resonance with the primary resonance coil.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to wireless power, and more particularly,to a wireless power transmission apparatus and a coil structure forimplementing the wireless power transmission apparatus.

Related Art

Generally, in order for a portable terminal such as a mobile phone, anotebook, and a PDA to be charged, the portable terminal needs toreceive electric energy (or electric power) from an external charger.The portable terminal includes a battery cell for storing electricenergy that supplied and a circuit for charging and discharging(supplying electric energy to the portable terminal) of the batterycell.

Electrical connection methods between a battery cell and a charger forcharging the battery cell with electrical energy include a terminalsupply method in which commercial power is supplied and converted into avoltage and a current corresponding to the battery cell and electricalenergy is supplied to the battery cell through a terminal of thecorresponding battery cell.

This terminal supply method is accompanied by the use of physical cablesor wires. Accordingly, when much equipment of terminal supply method isused, many cables occupy a considerable work space, and are difficult toarrange, thereby deteriorating the appearance. Also, the terminal supplymethod may cause limitations such as an instantaneous dischargephenomenon due to potential differences between terminals, a burnout andfire due to sticking of foreign objects, a natural discharge, a lifespanand performance reduction of a battery pack and the like.

In recent years, charging systems (hereinafter, referred to as wirelesspower transfer systems) and control methods using the wireless powertransmission method and control methods are being proposed in order toovercome the above-mentioned limitations. The wireless powertransmission method is also referred to as a contactless powertransmission method or a no point of contact power transmission method.The wireless power transfer system includes a wireless powertransmission apparatus for supplying electric energy by a wireless powertransmission method and a wireless power reception apparatus forreceiving electric energy wirelessly supplied from the wireless powertransmission apparatus to charge a battery cell. As technologies ofwirelessly transmitting power, there are magnetic induction coupling andmagnetic resonance coupling.

SUMMARY OF THE INVENTION

The present invention provides a wireless power transmission apparatusand a hybrid type coil structure for implementing the wireless powertransmission apparatus.

The present invention also provides a method of performing wirelesspower transmission based on another technical hybrid type coilstructure.

In an aspect, a wireless power transmission apparatus is provided. Thewireless power transmission apparatus includes: a primary core includinga primary resonant coil wound in a spiral form and a first inductivecoil supplying power to the primary resonant coil in a contactless formwith an input terminal or an output terminal of the primary resonantcoil and wound in a spiral form on the substantially same plane aroundthe substantially same center point as a center point of the primaryresonant coil, and generating at least one of magnetic induction andmagnetic resonance by a driving signal to transmit wireless power to awireless power reception apparatus; a driving circuit connected to theprimary core and applying the driving signal to the primary core; acontrol circuit connected to the primary core and the driving circuitand providing a control signal for controlling a switch of the primarycore; and a measurement circuit for measuring a current or voltage ofthe primary core.

The wireless power transmission apparatus may further include aplurality of capacitors connected to both ends of the switch of theprimary core.

The primary resonant coil and the primary inductive coil may be woundside by side at an inner side close to the center point and the primaryresonant coil may be extended and wound at an outer side distant fromthe center point.

The primary resonant coil may be extended and wound at an inner sideclose to the center point and the primary resonant coil and the primaryinductive coil may be wound side by side at an outer side distant fromthe center point.

The primary resonant coil and the primary inductive coil may be woundsuch that a pattern in which the primary inductive coils are duallywound side by side and the primary resonant coil is adjacently woundoutside the primary inductive coils wound side by side is repeated atleast once.

In another aspect, a wireless power transmission coil structure isprovided. The wireless power transmission coil structure includes: aprimary resonant coil wound in a spiral form around a center point; afirst inductive coil supplying power to the primary resonant coil in acontactless form with an input terminal or an output terminal of theprimary resonant coil and wound in a spiral form on the substantiallysame plane around the substantially same center point as the centerpoint of the primary resonant coil; a switch disposed in parallel withthe primary resonant coil to control ON and OFF of the operation of theprimary resonant coil; and a capacitor coupled to the primary resonantcoil so as to form a magnetic resonance with the primary resonant coil.

Here, the switch may be turned on in a resonant operation mode, and theswitch may be turned off in an inductive operation mode.

The switch may include a plurality of Field Effect Transistors (FETs)that maintain a switch-on state regardless of a phase of a voltageapplied to the primary resonant coil.

The primary resonant coil and the primary inductive coil may be woundside by side at an inner side close to the center point and the primaryresonant coil may be extended and wound at an outer side distant fromthe center point.

The primary resonant coil may be extended and wound at an inner sideclose to the center point and the primary resonant coil and the primaryinductive coil may be wound side by side at an outer side distant fromthe center point.

The primary resonant coil and the primary inductive coil may be woundsuch that a pattern in which the primary inductive coils are duallywound side by side and the primary resonant coil is adjacently woundoutside the primary inductive coils wound side by side is repeated atleast once.

In another aspect, a wireless power transmission method is provided. Thewireless power transmission method includes: transmitting powergenerated by magnetic induction in a primary inductive coil wound in aspiral form around a center point to a primary resonant coil, here, theprimary resonant coil being wound in a spiral form on the same planearound the substantially same center point as the center point and beingprovided in a contactless form with an input terminal and an outputterminal of the primary inductive coil; generating a magnetic resonancein the primary resonant coil and transmitting the power to a wirelesspower reception apparatus; and controlling ON and OFF of the operationof the primary resonant coil based on a switch disposed in parallel withthe primary resonant coil, wherein the controlling of ON and OFF of theoperation includes turning on the switch in a resonant operation modeand turning off the switch in an inductive operation mode.

The primary resonant coil and the primary inductive coil may be woundside by side at an inner side close to the center point and the primaryresonant coil may be extended and wound at an outer side distant fromthe center point.

The primary resonant coil may be extended and wound at an inner sideclose to the center point and the primary resonant coil and the primaryinductive coil may be wound side by side at an outer side distant fromthe center point.

The primary resonant coil and the primary inductive coil may be woundsuch that a pattern in which the primary inductive coils are duallywound side by side and the primary resonant coil is adjacently woundoutside the primary inductive coils wound side by side is repeated atleast once.

According to an embodiment, the wireless power can be stably transmittedby maintaining a constant value of the quality factor (Q-factor) of theresonant coil. Also, by implementing two kinds of coils having inductionand resonance functions on the same plane, volume and unit cost can beminimized when the product is implemented. On the other hand,induction-based wireless charging and resonance-based wireless chargingcan be independently implemented by mounting a switch function onto acoil having a resonance function.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a view illustrating components of a wireless power transfersystem according to an embodiment of the present invention.

FIG. 2 is a view illustrating a wireless power transmission apparatusaccording to an embodiment of the present invention.

FIG. 3 is a view illustrating a hybrid type according to an embodimentof the present invention.

FIG. 4 is a view illustrating a hybrid type according to anotherembodiment of the present invention.

FIG. 5 is a view illustrating the hybrid type of FIG. 4 whoseinput/output terminals are separated into an inner side and an outerside.

FIG. 6 is a view illustrating a hybrid type according to anotherembodiment of the present invention.

FIG. 7 is a view illustrating a hybrid type according to anotherembodiment of the present invention.

FIG. 8 is a view illustrating a primary core including at least oneswitch according to an embodiment of the present invention.

FIG. 9 is a view illustrating a primary core including at least oneswitch according to another embodiment of the present invention.

FIG. 10 is a flowchart illustrating an operation for driving a hybridtype of coil according to an embodiment of the present invention.

FIG. 11 is a flowchart illustrating an operation of a wireless powertransmission apparatus according to an embodiment of the presentinvention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

The term ‘wireless power’ below is used to mean any type of energyassociated with an electric field, a magnetic field, and anelectromagnetic field transmitted from a wireless power transmissionapparatus to a wireless power reception apparatus without the use ofphysical electromagnetic conductors. The wireless power may also bereferred to as a power signal or wireless energy, and may denote anoscillating magnetic flux enclosed by the primary and secondary coils.For example, power conversion in a system to wirelessly charge devicesincluding mobile phones, cordless phones, iPods, MP3 players, headsetsand the like will be described herein. In this disclosure, the basicprinciples of wireless power transmission include, for example, bothmagnetic induction coupling and magnetic resonance coupling that usesfrequencies of less than 30 MHz. However, various frequencies at whichlicense-exempt operations at relatively high radiation levels, forexample, less than 135 kHz (LF) or at 13.56 MHz (HF) are allowed may beused.

FIG. 1 a view illustrating components of a wireless power transfersystem according to an embodiment of the present invention.

Referring to FIG. 1, a wireless power transfer system 100 may include awireless power transmission apparatus 110 and one wireless powerreception apparatus 150-1 or n wireless power reception apparatuses150-1 to 150-n.

The wireless power transmission apparatus 110 includes a primary core.The primary core may include one or more primary coils 115. The primarycore may further include at least one capacitor coupled to the primarycoil 115. The wireless power transmission apparatus 110 may have anysuitable form, but one preferred form is a flat platform with a powertransfer surface. Here, each of the wireless power reception apparatuses150-1 to 150-n may be located on the platform or therearound.

The wireless power reception apparatuses 150-1 to 150-n are detachablefrom the wireless power transmission apparatus 110, and each of thewireless power reception apparatuses 150-1 to 150-n includes a secondarycore coupled with an electromagnetic field generated by the primary coreof the wireless power transmission apparatus 110 when being close to thewireless power transmission apparatus 110. The secondary core mayinclude one or more second coils 155. The secondary core may furtherinclude at least one capacitor coupled to the secondary coil 155.

The wireless power transmission apparatus 110 transmits power to thewireless power reception apparatuses 150-1 to 150-n without directelectrical contact. In this case, the primary core and the secondarycore are referred to as being magnetic-induction-coupled ormagnetic-resonance-coupled to each other. The primary coil 115 or thesecondary coil 125 may have any suitable shape, but may be a copper wirewound around a formation having a high permeability, such ferrite oramorphous metal.

The wireless power reception apparatuses 150-1 to 150-n are connected toan external load (not shown, here, also referred to as an actual load ofthe wireless power reception apparatus), and supply power wirelesslyreceived from the wireless power transmission apparatus 110 to theexternal load. For example, the wireless power reception apparatuses150-1 to 150-n may each carry received power to an object that consumesor stores power, such as a portable electric or electronic device, or arechargeable battery cell or battery.

FIG. 2 is a view illustrating a wireless power transmission apparatusaccording to an embodiment of the present invention.

Referring to FIG. 2, a wireless power transmission apparatus 200includes a primary core 210, a driving circuit 220, a control circuit230, and a measurement circuit 240.

The primary core 210 includes at least one primary coil. For example,the primary core 210 may include at least one primary resonant coil andat least one primary inductive coil. Thus, the resonant coil and theinductive coil may be included in a single core or a single wirelesspower transmission apparatus as a single module, which can be called ahybrid type. In the hybrid type, the primary resonant coil is a coilused to transmit wireless power to the wireless power receptionapparatus by magnetic resonance coupling, and the primary inductive coilis a coil used to transmit wireless power to the wireless powerreception apparatus by magnetic induction coupling. In this case, theprimary core 210 may further include a capacitor coupled to the primaryresonant coil so as to form a magnetic resonance with the primaryresonant coil. The magnetic induction method may be used to supply ortransmit the corresponding power when the primary core 210 transmitswireless power by the magnetic resonance method. Accordingly, theprimary inductive coil may also be referred to as a drive coil.

In the hybrid type, at least one primary resonant coil and at least oneprimary inductive coil may be coupled based on various windingstructures and arrangements.

In one aspect, the hybrid type may have the structure of FIG. 3.Referring to FIG. 3, a primary resonant coil 310 and a primary inductivecoil 320 are applied on the same plane. That is, the primary resonantcoil 310 and the primary inductive coil 320 are disposed so as to betogether wound around the substantially same center point on the sameplane. Also, the primary resonant coil 310 and the primary inductivecoil 320 are wound side by side. In other words, the primary resonantcoil 310 and the primary inductive coil 320 are wound in a bi-filartype.

The winding of the primary coil (resonant or inductive coil) and thesecondary coil (inductive or resonant coil) side by side means at leastone repetition of the pattern in which the secondary coil is wound justoutside the winding of the primary coil and the primary coil is woundjust outside the winding of the secondary coil. Also, the bi-filar typemeans that two independent coils are wound adjacent to each other inparallel. Accordingly, the bi-filar type is provided with two inputs andtwo outputs, respectively. The form in which two coils are wound side byside may be called the bi-filar type.

Although physically adjacent to each other, the primary resonant coil310 and the primary inductive coil 320 may not be electrically connectedto each other. The primary resonant coil 310 and the primary inductivecoil 320 may each have a spiral shape. A capacitor forming a magneticresonance with the primary resonant coil 310 may be coupled to both endsof the primary resonant coil 310.

Thus, when the inductive coil and the resonant coil are separated ordistant from each other on different planes, the thickness (or height)of the primary core is relatively large, thereby increasing the volumeand increase the cost. However, according to the structure shown in FIG.3, even though the inductive coil and the resonant coil are separatedfrom each other, since the inductive coil and the resonant coil arecoupled on the same plane, an increase of volume can be prevented, andan actual product can be very easily implemented. Also, since thevariation of the Q-factor of the resonant coil due to the loadmodulation can be minimized and the resonant coil and the inductive coilcan be individually controlled, simultaneous power control can be easilyperformed, thereby improving the efficiency, and a distance between thewireless power transmission apparatus and the wireless power receptionapparatus can be significantly increased.

In another aspect, at least one primary resonant coil and at least oneprimary inductive coil may have the coupling structure of FIG. 4.Referring to FIG. 4, a primary resonant coil 410 and a primary inductivecoil 420 are applied on the same plane. That is, the primary resonantcoil 410 and the primary inductive coil 420 are disposed so as to betogether wound around the substantially same center point on the sameplane. Also, the primary resonant coil 410 is configured to beseparately extended to be wound around the outer side of the primaryinductive coil 420 and thus match the wavelength of the primary resonantcoil 410 with the resonance frequency. In other words, the primaryresonant coil 410 and the primary inductive coil 420 are wound side byside from the center point to the radius r (inward), and only theprimary resonant coil 410 is wound from the radius r to the radiusr′(>r)(outward). Accordingly, the winding interval of the primaryresonant coil 410 on the inner side is larger than the winding intervalof the primary resonant coil 410 on the outer side. In other words, thefirst resonant coil 410 has a wider winding interval from the inner sideto the outer side. This is because, at the inner side, the primaryinductive coil 420 is interposed in every winding (that is, between thewindings) of the primary resonant coil 410.

This hybrid type includes a primary inductive coil 420 configured to bewound in a spiral form at the inner side and generate power to betransmitted to the wireless power reception apparatus and a primaryresonant coil 410 wound side by side together with the primary inductivecoil 420 at the inner side of the same center on the substantially sameplane and separately wound at the outer side to deliver the generatedpower to a wireless power reception apparatus. Although physicallyadjacent to each other, the primary resonant coil 410 and the primaryinductive coil 420 may not be electrically connected to each other. Theprimary resonant coil 410 and the primary inductive coil 420 may eachhave a spiral shape. A capacitor forming a magnetic resonance with theprimary resonant coil 410 may be coupled to both ends of the primaryresonant coil 410. It can be seen that the hybrid type of FIG. 4 has astructure as shown in FIG. 5 when the input and output terminals areseparated into the inner side and the outer side.

Referring to FIG. 5, a primary inner resonant coil 510 and a primaryinductive coil 520 are wound side by side at the inner side on thesubstantially same plane around the substantially same center point.That is, at the inner side, the primary inner resonant coil 510 and theprimary inductive coil 520 are wound in a bi-filar type, and terminals Aand A′ are the input and output of the primary inductive coil 520,respectively. Also, terminals C and B′ are the input and output of theprimary internal resonant coil 510, respectively. On the other hand, atthe outer side, only the primary outer resonant coil 511 is wound in asingle type, and terminals B and C′ are the input and the output of theprimary outer resonant coil 511, respectively. The terminal C isconnected to the terminal C′ such that the primary inner resonant coil510 and the primary outer resonant coil 511 are electrically connectedto each other to form a primary resonant coil. Meanwhile, the connectionrelation of remaining inputs and outputs are as follows. Terminals A andA′ are connected to a structure (inductive Tx) for generating andtransmitting power based on the magnetic induction as the input and theoutput, respectively. The terminal B of the primary inner resonant coil510 of the bi-filar type and the terminal B′ of the primary outerresonant coil 511 of the single type are connected to a capacitor forconstituting a resonance circuit together with the primary resonantcoil, respectively.

Here, the length of the primary resonant coil may be designed andmanufactured in accordance with the wavelength of the resonancefrequency so as to optimize the resonant power radiation. For example,when the wavelength of the resonance frequency is k, the length of theprimary resonant coil may have a value obtained by dividing thewavelength of the resonance frequency by the power of 2 such as λ, λ/2,λ/4, λ/8, and λ/2n.

Thus, when the primary inductive coil and the primary resonant coil arefunctionally and physically separated as a bi-filar type, there is aneffect of becoming insensitive to changes in impedance and/or loadbetween the wireless power transmission apparatus and the wireless powerreception apparatus. Furthermore, by maintaining a constant value of thequality factor (Q-factor) of the resonant coil, the wireless power canbe stably transmitted. Also, by implementing two kinds of coils havinginduction and resonance functions on the same plane, volume and unitcost can be minimized when the product is implemented. On the otherhand, induction-based wireless charging and resonance-based wirelesscharging can be independently implemented by mounting a switch functiononto a coil having a resonance function.

In another aspect, at least one primary resonant coil and at least oneprimary inductive coil may have the coupling structure of FIG. 6.

Referring to FIG. 6, primary resonant coils 610 and 611 and a primaryinductive coil 620 are applied on the same plane. That is, the primaryresonant coils 610 and 611 and the primary inductive coil 620 aredisposed so as to be together wound around the substantially same centerpoint on the same plane. Also, the primary inner resonant coil 610 isconfigured to be separately extended and wound in the inner side of theprimary inductive coil 620 and thus match the wavelength of the primaryresonant coils 610 and 611 with the resonance frequency. In other words,the primary inner resonant coil 610 is wound alone from the center pointto the radius r (inward), and the primary inductive coil 620 and theprimary outer resonant coil 611 are together wound side by side from theradius r to the radius r′(>r)(outward). Accordingly, the windinginterval of the primary resonant coil 610 on the outer side is largerthan the winding interval of the primary resonant coil 610 on the innerside. In other words, the first resonant coil 610 has a narrower windinginterval from the inner side to the outer side. This is because, at theouter side, the primary inductive coil 620 is interposed in everywinding (that is, between the windings) of the primary resonant coil610.

This hybrid type includes a primary inner resonant coil 610 configuredto be wound in a spiral form at the inner side to transmit power to thewireless power reception apparatus and a primary inductive coil 620configured to be wound side by side together with the primary outerresonant coil 611 at the outer side around the substantially same centerpoint on the substantially same plane as the primary inner resonant coil610 to generate and deliver the power.

In another aspect, at least one primary resonant coil and at least oneprimary inductive coil may have the coupling structure of FIG. 7.

Referring to FIG. 7, a primary resonant coil 710 and a primary inductivecoil 720 are applied on the same plane. That is, the primary resonantcoil 710 and the primary inductive coil 720 are disposed so as to betogether wound around the substantially same center point on the sameplane. The primary inductive coil 720 is wound in the bi-filar type, twoof which are wound side by side in parallel. The primary inductive coils720 of the bi-filar type are wound side by side together with theprimary resonant coil 710 of the single type. In other words, a patternin which the primary inductive coils 720 are dually wound and theprimary resonant coil 710 is wound just outside the primary inductivecoil 720 is repeated at least one time. Thus, the form in which threecoils are wound side by side may be called the tri-filar type. In thetri-filar type, one winding is added to the bi-filar type, and threeindependent coils are wound in parallel adjacent to each other.Accordingly, the tri-filar type is provided with three inputs and threeoutputs. In FIG. 7, the primary resonant coil 710 of the bi-filar typeand the primary resonant coil 710 of the single type are combined toimplement the tri-filar type. On the contrary to this, the primaryresonant coil 710 of the bi-filar type and the primary inductive coil720 of the single type may be combined to implement a tri-filar type.

Referring again to FIG. 2, the primary core 210 may include a pluralityof primary coils, at least one capacitor coupled to the plurality ofprimary coils, and at least one switch (not shown) that performsswitching of the plurality of primary coils. The primary core 210generates an electromagnetic field according to a driving signal appliedfrom the driving circuit 220, and transmits wireless power to thewireless power reception apparatus through the electromagnetic field.

FIG. 8 is a view illustrating a primary core including at least oneswitch according to an embodiment of the present invention.

Referring to FIG. 8, a primary core 800 may include a hybrid type coilstructure in which a primary inductive coil and a primary resonant coilare coupled, a structure (inductive Tx) 850 for generating andtransmitting power based on magnetic induction, a switch 830 forperforming switching of the primary resonant coil, and a plurality ofcapacitors 840 and 845 connected to both ends of the switch 830. All ofthe hybrid types disclosed in this specification may be applied to thehybrid type coil structure of FIG. 8.

As an example of the operation of the switch 830, the switch 830 isturned off in a first wireless power transmission mode, and is turned onin a second wireless power transmission mode. Here, the first wirelesspower transmission mode is a mode in which wireless power transmissionby the magnetic induction method is performed but wireless powertransmission by the magnetic resonance method is not performed, that is,a mode in which only the first inductive coil operates. Also, the secondwireless power transmission mode is a mode in which wireless powertransmission by the magnetic resonance method is performed, and is amode in which the primary resonant coil operates. In the second wirelesspower transmission mode, the wireless power transmission by the magneticinduction method as well as the magnetic resonance method may betogether performed. In this case, both the primary resonant coil and theprimary inductive coil may operate. The switch 830 may be turned on oroff according to the kind of coil used for the wireless powertransmission mode. Also, a control signal for controlling the switch 830is applied to the switch 830. This control signal may be provided by thecontrol circuit 230.

FIG. 9 is a view illustrating a primary core including at least oneswitch according to another embodiment of the present invention.

Referring to FIG. 9, a primary core 900 may include a hybrid type coilstructure in which a primary inductive coil and a primary resonant coilare coupled, a structure (inductive Tx) 950 for generating andtransmitting power based on magnetic induction, a switch 930 forperforming switching of the primary resonant coil, and a plurality ofcapacitors 940 and 945 connected to both ends of the switch 930. All ofthe hybrid types disclosed in this specification may be applied to thehybrid type coil structure of FIG. 9.

Unlike the switch 830 shown in FIG. 8, the switch 930 has a structure inwhich two Field Effect Transistors (FETs) are configured in parallel inboth directions of a primary resonant coil. Thus, even though a voltageapplied to the primary resonant coil or the phase of the voltage of theprimary resonant coil is changed, the switch-on state is maintained.

As an example of the operation of the switch 930, the FETs are turnedoff in a first wireless power transmission mode, and are turned on in asecond wireless power transmission mode. Here, the first wireless powertransmission mode is a mode in which wireless power transmission by themagnetic induction method is performed but wireless power transmissionby the magnetic resonance method is not performed, that is, a mode inwhich only the first inductive coil operates. Also, the second wirelesspower transmission mode is a mode in which wireless power transmissionby the magnetic resonance method is performed, and is a mode in whichthe primary resonant coil operates. In the second wireless powertransmission mode, the wireless power transmission by the magneticinduction method as well as the magnetic resonance method may betogether performed. In this case, both the primary resonant coil and theprimary inductive coil may operate. The FETs may be turned on or offaccording to the kind of coil used for the wireless power transmissionmode. Also, a control signal for controlling the switch 930 is appliedto the switch 930. This control signal may be provided by the controlcircuit 230.

Referring again to FIG. 2, the driving circuit 220 is connected to theprimary core 210, and applies driving signals to the primary core 210.

The control circuit 230 is connected to the driving circuit 220, andgenerates a control signal 231 that controls an AC signal required whenthe primary core 210 generates an induction magnetic field or incurs amagnetic resonance. The control circuit 230, as a sort of processor, mayinclude Application-Specific Integrated Circuits (ASICs), other chipsets, logic circuits and/or data processing devices.

Also, the control circuit 230 may be connected to the primary core 210to provide a control signal for controlling a switch of the primary core210. Particularly, when the primary coil included in the primary core210 is a hybrid type, the control circuit 230 may perform an operationfor driving a hybrid type of coil. As an example, the control circuit230 performs operations according to the procedure shown in FIG. 10.Referring to FIG. 10, the control circuit 230 determines whether or notthe wireless power reception apparatus is a magnetic resonance-basedwireless power reception apparatus (S1000). That is, the control circuit230 checks whether or not the wireless power reception apparatus Rx is aresonance type. If the wireless power reception apparatus is a resonancetype, the control circuit 230 applies a control signal for turning onthe switch to the primary core 210 (S1005). That is, the primary core210 turns on the switch, and thus the wireless power transmissionapparatus enters the second wireless power transmission mode (S1010).

On the other hand, if the wireless power reception apparatus is aninduction type, the control circuit 230 applies a control signal forturning off the switch to the primary core 210 (S1015). That is, theprimary core 210 turns off the switch, and thus the wireless powertransmission apparatus enters the first wireless power transmission mode(S1020).

The measurement circuit 240 measures a current or a voltage flowing inthe primary coil. In particular, the current measured by the measurementcircuit 240 may be an alternating current. The measurement circuit 240may be a current sensor or a voltage sensor. Alternatively, themeasurement circuit 240 may lower a high current flowing in the primarycoil to a low current for use, or may be a transformer that lowers ahigh voltage applied to the primary coil to a low voltage.

Although not shown in the drawings, the wireless power transmissionapparatus 200 may further include at least one of a storage device and acommunication module wirelessly exchanging data with the wireless powerreception apparatus. The communication module may include a RadioFrequency (RF) antenna for transmitting or receiving a signal and acircuit for processing a wireless signal. The storage device may includedisk drives, Read-Only Memories (ROMs), Random Access Memories (RAMs),flash memories, memory cards, and storage media.

FIG. 11 is a flowchart illustrating an operation of a wireless powertransmission apparatus according to an embodiment of the presentinvention.

Referring to FIG. 11, the wireless power transmission apparatus is in acharging standby state until a wireless power reception apparatus isdetected (S1100). This state may be referred to as a selection phase.

At this time, the wireless power transmission apparatus continuouslydetects an object to which power is to be transmitted (S1105). Thisstate may be referred to as a ping phase. In operation S1105, thewireless power transmission apparatus performs an object detectionoperation.

If an object is not detected, the wireless power transmission apparatusreturns to the charging standby state (S1100).

If an object is detected, the wireless power transmission apparatusdetermines whether or not the detected object is a wireless powerreception apparatus capable of normally receiving wireless power(S1110). This state may be referred to as an identification phase or anidentification and negotiation phase. In the identification phase, thewireless power transmission apparatus may receive various kinds ofinformation related to the wireless power reception apparatus from thewireless power reception apparatus. Also, in the negotiation phase, thewireless power transmission apparatus and the wireless power receptionapparatus may exchange various kinds of information required forwireless charging with each other. In order to exchange information, thewireless power transmission apparatus and the wireless power receptionapparatus may use a load modulation method through the primary core, ormay include a separate communication module (e.g., Bluetooth) to performcommunication.

If the detected object is not a wireless power reception apparatus, thewireless power transmission apparatus interrupts power (S1115).

If the detected object is a wireless power reception apparatus, thewireless power transmission apparatus enters the charging mode (S1120).In the charging mode, the wireless power transmission apparatus applieselectric power to the primary core to generate magnetic induction ormagnetic resonance. In particular, when the primary coil included in theprimary core is a hybrid type, the wireless power transmission apparatusmay additionally perform the operations according to the procedure shownin FIG. 10.

The wireless power transmission apparatus measures a current flowing inthe primary coil or a voltage applied to the primary coil (S1125).

When a foreign object is detected, the wireless power transmissionapparatus interrupts wireless power that is being transmitted to thewireless power reception apparatus (S1115). The detecting of foreignobject may be performed before operation S1120.

On the other hand, when a foreign object is not detected, the wirelesspower transmission apparatus continuously transmits power to thewireless power reception apparatus (S1130).

The invention has been described in detail with reference to exemplaryembodiments thereof. However, it will be appreciated by those skilled inthe art that changes may be made in these embodiments without departingfrom the principles and spirit of the invention, the scope of which isdefined in the appended claims and their equivalents. Therefore, thepresent invention covers all embodiments falling within the scope of thefollowing claims, rather than being limited to the above-describedembodiments.

What is claimed is:
 1. A wireless power transmission apparatuscomprising: a primary core comprising a primary resonant coil wound in aspiral form and a first inductive coil supplying power to the primaryresonant coil in a contactless form with an input terminal or an outputterminal of the primary resonant coil and wound in a spiral form on thesubstantially same plane around the substantially same center point as acenter point of the primary resonant coil, and generating at least oneof magnetic induction and magnetic resonance by a driving signal totransmit wireless power to a wireless power reception apparatus; adriving circuit connected to the primary core and applying the drivingsignal to the primary core; a control circuit connected to the primarycore and the driving circuit and providing a control signal forcontrolling a switch of the primary core; and a measurement circuit formeasuring a current or voltage of the primary core.
 2. The wirelesspower transmission apparatus of claim 1, further comprising a pluralityof capacitors connected to both ends of the switch of the primary core.3. The wireless power transmission apparatus of claim 1, wherein theprimary resonant coil and the primary inductive coil are wound side byside at an inner side close to the center point and the primary resonantcoil is extended and wound at an outer side distant from the centerpoint.
 4. The wireless power transmission apparatus of claim 1, whereinthe primary resonant coil is extended and wound at an inner side closeto the center point and the primary resonant coil and the primaryinductive coil are wound side by side at an outer side distant from thecenter point.
 5. The wireless power transmission apparatus of claim 1,wherein the primary resonant coil and the primary inductive coil arewound such that a pattern in which the primary inductive coil is duallywound side by side and the primary resonant coil is adjacently woundoutside the primary inductive coil is repeated at least once.
 6. Awireless power transmission coil structure comprising: a primaryresonant coil wound in a spiral form around a center point; a firstinductive coil supplying power to the primary resonant coil in acontactless form with an input terminal or an output terminal of theprimary resonant coil and wound in a spiral form on the substantiallysame plane around the substantially same center point as the centerpoint of the primary resonant coil; a switch disposed in parallel withthe primary resonant coil to control ON and OFF of the operation of theprimary resonant coil; and a capacitor coupled to the primary resonantcoil so as to form a magnetic resonance with the primary resonant coil,wherein the switch is turned on in a resonant operation mode, and theswitch is turned off in an inductive operation mode.
 7. The wirelesspower transmission coil structure of claim 6, wherein the switchcomprises a plurality of Field Effect Transistors (FETs) that maintain aswitch-on state regardless of a phase of a voltage applied to theprimary resonant coil.
 8. The wireless power transmission coil structureof claim 6, wherein the primary resonant coil and the primary inductivecoil are wound side by side at an inner side close to the center pointand the primary resonant coil is extended and wound at an outer sidedistant from the center point.
 9. The wireless power transmission coilstructure of claim 6, wherein the primary resonant coil is extended andwound at an inner side close to the center point and the primaryresonant coil and the primary inductive coil are wound side by side atan outer side distant from the center point.
 10. The wireless powertransmission coil structure of claim 6, wherein the primary resonantcoil and the primary inductive coil are wound such that a pattern inwhich the primary inductive coil is dually wound side by side and theprimary resonant coil is adjacently wound outside the primary inductivecoil is repeated at least once.
 11. A wireless power transmission methodcomprising: transmitting power generated by magnetic induction in aprimary inductive coil wound in a spiral form around a center point to aprimary resonant coil, here, the primary resonant coil being wound in aspiral form on the same plane around the substantially same center pointas the center point and being provided in a contactless form with aninput terminal and an output terminal of the primary inductive coil;generating a magnetic resonance in the primary resonant coil andtransmitting the power to a wireless power reception apparatus; andcontrolling ON and OFF of the operation of the primary resonant coilbased on a switch disposed in parallel with the primary resonant coil,wherein the controlling of ON and OFF of the operation comprises turningon the switch in a resonant operation mode and turning off the switch inan inductive operation mode.
 12. The wireless power transmission methodof claim 11, wherein the primary resonant coil and the primary inductivecoil are wound side by side at an inner side close to the center pointand the primary resonant coil is extended and wound at an outer sidedistant from the center point.
 13. The wireless power transmissionmethod of claim 11, wherein the primary resonant coil is extended andwound at an inner side close to the center point and the primaryresonant coil and the primary inductive coil are wound side by side atan outer side distant from the center point.
 14. The wireless powertransmission method of claim 11, wherein the primary resonant coil andthe primary inductive coil are wound such that a pattern in which theprimary inductive coil is dually wound side by side and the primaryresonant coil is adjacently wound outside the primary inductive coil isrepeated at least once.